gas supply system

Abstract

The objective is to improve the utilization efficiency of gas stored in a main tank with a simple configuration in a gas supply system that supplies gas from a main tank to a utilization device. [Solution] The gas supply system 20 includes a main tank 30 for storing gas to be supplied to the fuel cell system 10, an auxiliary tank 40 for storing gas at or above the starting limit pressure of the fuel cell system 10, and a CPU 82 that switches between the main tank 30 and the auxiliary tank 40 to supply gas to the fuel cell system 10 based on the supply pressure of the gas supplied from the main tank 30 to the fuel cell system 10, the starting limit pressure of the fuel cell system 10, and the operating limit pressure of the fuel cell system 10 which is lower than the starting limit pressure.

Description

Technical Field

[0001] The present invention relates to a gas supply system.

Background Art

[0002] A hydrogen station is known that includes a compressor that pressurizes hydrogen, and an accumulator unit having a plurality of accumulators capable of storing the hydrogen pressurized by the compressor, and fills a hydrogen fuel tank with the hydrogen stored in the accumulator unit, wherein the hydrogen in some of the plurality of accumulators can be pressurized by the compressor and controlled to be transferred to other accumulators (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0004] By the way, as a utilization device that uses gas, for example, a fuel cell is known. A fuel cell generates electric power using hydrogen gas supplied from a tank as fuel.

[0005] However, in a fuel cell, the required pressure of hydrogen gas at the start of power generation (hereinafter referred to as "startup limit pressure") is higher than the required pressure of hydrogen gas for continuing power generation (hereinafter referred to as "operation limit pressure").

[0006] Therefore, when power generation of the fuel cell is stopped, if the residual pressure of the hydrogen gas in the tank is equal to or higher than the operation limit pressure but lower than the startup limit pressure, the fuel cell cannot resume power generation, and the utilization efficiency of the hydrogen gas stored in the tank decreases.

[0007] One possible solution is to use a compressor to increase the pressure of the hydrogen gas supplied from the tank to the fuel cell to above the starting limit pressure.

[0008] However, in this case, large-scale equipment such as compressors would be required.

[0009] In consideration of the above facts, the present invention aims to improve the utilization efficiency of gas stored in a main tank with a simple configuration in a gas supply system that supplies gas from a main tank to a utilization device. [Means for solving the problem]

[0010] The gas supply system according to claim 1 comprises a main tank for storing gas to be supplied to a user device, an auxiliary tank for storing gas at or above the starting limit pressure of the user device, and a control unit for switching between the main tank and the auxiliary tank to supply gas to the user device based on the supply pressure of the gas supplied from the main tank to the user device, the starting limit pressure of the user device, and the operating limit pressure of the user device which is lower than the starting limit pressure.

[0011] According to the gas supply system of claim 1, the main tank stores the gas to be supplied to the user device. The auxiliary tank stores gas at or above the starting limit pressure of the user device.

[0012] Here, the control unit switches the tank supplying gas to the utilization device between the main tank and the auxiliary tank, based on the supply pressure of the gas supplied from the main tank to the utilization device, the starting limit pressure of the utilization device, and the operating limit pressure of the utilization device which is lower than the starting limit pressure.

[0013] As a result, for example, if the gas supply pressure from the main tank to the user device is below the user device's startup limit pressure but above the operating limit pressure, the control unit switches the tank supplying gas to the user device from the main tank to the auxiliary tank. This allows the user device to be started even if the gas supply pressure from the main tank to the user device is below the user device's startup limit pressure.

[0014] Then, after the user device is started up, the control unit switches the tank supplying gas to the user device from the auxiliary tank to the main tank. This ensures that gas above the operating limit pressure is supplied from the main tank to the user device. In other words, the gas stored in the main tank can be used.

[0015] Thus, in this invention, the utilization efficiency of the gas stored in the main tank can be increased with a simple configuration in which gas is supplied from an auxiliary tank to the utilization device.

[0016] The gas supply system according to claim 2 is the gas supply system according to claim 1, wherein the control unit, when the utilization device is started, supplies gas from the auxiliary tank to the utilization device if the supply pressure of the gas supplied from the main tank to the utilization device is less than the starting limit pressure and greater than or equal to the operating limit pressure, and supplies gas from the main tank to the utilization device after the utilization device has been started.

[0017] According to the gas supply system of claim 2, when the user device is started, the control unit supplies gas from the auxiliary tank to the user device if the supply pressure of the gas supplied from the main tank to the user device is less than the starting limit pressure and greater than or equal to the operating limit pressure. After the user device is started, the control unit supplies gas from the main tank to the user device. This makes it possible to use the gas stored in the main tank.

[0018] Therefore, the present invention makes it possible to improve the utilization efficiency of the gas stored in the main tank.

[0019] The gas supply system according to claim 3 is the gas supply system according to claim 1 or 2, wherein when the utilization device is started, if the supply pressure of the gas supplied from the main tank to the utilization device is equal to or higher than the startup limit pressure, the control unit causes the gas to be supplied from the main tank to the utilization device, and if the supply pressure of the gas supplied from the auxiliary tank to the utilization device is lower than the startup limit pressure, the control unit causes the gas to be supplied from the main tank to the auxiliary tank.

[0020] According to the gas supply system of claim 3, when the utilization device is started, if the supply pressure of the gas supplied from the main tank to the utilization device is equal to or higher than the startup limit pressure, the control unit causes the gas to be supplied from the main tank to the utilization device. Thereby, the utilization device can be started.

[0021] Further, when the supply pressure of the gas supplied from the auxiliary tank to the utilization device is lower than the startup limit pressure, the control unit causes the gas to be supplied from the main tank to the auxiliary tank. Thereby, the auxiliary tank can store gas at a pressure equal to or higher than the startup limit pressure of the utilization device.

[0022] The gas supply system according to claim 4 is the gas supply system according to claim 1, wherein the main tank is a hydrogen storage alloy tank, and the auxiliary tank is a hydrogen gas tank.

[0023] According to the gas supply system of claim 4, the main tank is a hydrogen storage alloy tank, and the auxiliary tank is a hydrogen gas tank. Thereby, the utilization efficiency of the hydrogen gas stored in the hydrogen storage alloy in the hydrogen storage alloy tank can be improved. [Effects of the Invention]

[0024] As described above, according to the present invention, in a gas supply system that supplies gas from a main tank to a utilization device, the utilization efficiency of the gas stored in the main tank can be improved with a simple configuration. [Brief Description of the Drawings]

[0025] [Figure 1] This is a system configuration diagram showing a fuel cell system to which a gas supply system according to an embodiment is applied. [Figure 2] This is a hardware configuration diagram of a control device according to an embodiment. [Figure 3] This is a system related diagram of the gas supply system and the fuel cell system shown in Figure 1. [Figure 4] This is a flowchart showing the flow of gas supply processing of the gas supply system shown in Figure 1. [Figure 5] This is a system configuration diagram corresponding to Figure 1, showing the operating state of the gas supply system. [Figure 6] This is a system configuration diagram corresponding to Figure 1, showing the operating state of the gas supply system. [Figure 7] This is a flowchart showing the flow of gas supply processing of the gas supply system shown in Figure 1. [Figure 8] This is a system configuration diagram corresponding to Figure 1, showing the operating state of the gas supply system. [Mode for Carrying Out the Invention]

[0026] Hereinafter, an embodiment will be described with reference to the drawings.

[0027] (Fuel Cell System) Figure 1 shows a fuel cell system 10 to which a gas supply system 20 according to the present embodiment is applied. The fuel cell system 10 is configured as a power generation system that generates power through a chemical reaction of hydrogen and oxygen. The fuel cell system 10 is an example of a utilization device.

[0028] The fuel cell system 10 includes, for example, a power generation unit that causes a chemical reaction between hydrogen and oxygen, a power storage unit that stores electric power generated by the power generation unit, and a current conversion unit that converts the current generated by the power generation unit.

[0029] Note that the configuration of the fuel cell system 10 can be modified as appropriate.

[0030] (Gas supply system) The gas supply system 20 is a system that supplies hydrogen gas as fuel to the fuel cell system 10. This gas supply system 20 includes a main tank 30, an auxiliary tank 40, and a control device 80.

[0031] (Main tank) The main tank 30 is a fuel tank for storing hydrogen gas as fuel for the fuel cell system 10. The main tank 30 is, for example, a hydrogen storage alloy tank. This main tank 30 contains a hydrogen storage alloy. The hydrogen storage alloy is an alloy capable of reversibly absorbing and releasing hydrogen gas.

[0032] Specifically, hydrogen gas is absorbed into the hydrogen storage alloy by cooling and pressurizing it. Conversely, hydrogen gas is released from the hydrogen storage alloy by heating and depressurizing it. For this reason, a heater (not shown) for heating the main tank 30 and a cooler (not shown) for cooling the main tank 30 are provided around the main tank 30.

[0033] Here, hydrogen storage alloys are capable of storing hydrogen gas at high density at room temperature and low pressure, compared to, for example, compressed hydrogen or liquid hydrogen. Furthermore, hydrogen storage alloys can release hydrogen by, for example, heating them from room temperature. The properties of hydrogen storage alloys vary depending on the type of alloy that makes up the alloy.

[0034] (Supply piping) The main tank 30 is connected to the fuel cell system 10 via a supply pipe 22. The supply pipe 22 is equipped with a pressure reducing valve 24, a main tank pressure gauge 32, and a supply pressure gauge 34.

[0035] The pressure reducing valve 24 reduces the supply pressure of hydrogen gas supplied to the fuel cell system 10 to a predetermined pressure (reference pressure) according to the specifications (requirements) of the fuel cell system 10. The pressure reducing valve 24 may be provided as needed and can be omitted as appropriate.

[0036] The main tank pressure gauge 32 is installed between the main tank 30 and the pressure reducing valve 24 in the supply piping 22. In other words, the main tank pressure gauge 32 is installed upstream of the pressure reducing valve 24 in the supply piping 22. This main tank pressure gauge 32 measures the supply pressure of hydrogen gas supplied from the main tank 30 to the pressure reducing valve 24. Note that the main tank pressure gauge 32 may be installed as needed and can be omitted as appropriate.

[0037] The supply pressure gauge 34 is installed between the pressure reducing valve 24 and the fuel cell system 10 in the supply piping 22. In other words, the supply pressure gauge 34 is installed downstream of the pressure reducing valve 24 in the supply piping 22. This supply pressure gauge 34 measures the supply pressure of the hydrogen gas that is reduced in pressure by the pressure reducing valve 24 and supplied to the fuel cell system 10. The control device 80, which will be described later, is electrically connected to the supply pressure gauge 34.

[0038] Furthermore, the supply piping 22 is equipped with a first on-off valve 36 and a second on-off valve 38. The first on-off valve 36 and the second on-off valve 38 are located on the main tank 30 side of the supply pressure gauge 34 in the supply piping 22. Each of the first on-off valve 36 and the second on-off valve 38 opens and closes the supply piping 22.

[0039] The first on-off valve 36 is located closer to the main tank 30 than the second on-off valve 38. In other words, the second on-off valve 38 is located closer to the fuel cell system 10 than the first on-off valve 36. The control device 80, which will be described later, is electrically connected to both the first on-off valve 36 and the second on-off valve 38.

[0040] (Auxiliary tank) In the aforementioned fuel cell system 10, the starting limit pressure of hydrogen gas at the start of power generation is higher than the operating limit pressure of hydrogen gas required to continue power generation. The reason for this is as follows:

[0041] In other words, when the fuel cell system 10 is in an operating state (power generation state) in which it is continuously generating electricity, the electrodes of the power generation unit become activated, and the power generation unit becomes hot. On the other hand, when the fuel cell system 10 starts generating electricity, i.e., at startup, the electrodes of the power generation unit are not activated, and the power generation unit becomes cold.

[0042] Therefore, when starting up the fuel cell system 10, more hydrogen gas is required than during operation to activate the electrodes of the power generation unit and raise the temperature of the power generation unit. Consequently, as mentioned above, in the fuel cell system 10, the starting limit pressure of hydrogen gas at the start of power generation is higher than the operating limit pressure of hydrogen gas required to continue power generation. In other words, in the fuel cell system 10, the operating limit pressure of hydrogen gas is lower than the starting limit pressure of hydrogen gas.

[0043] Therefore, for example, when the fuel cell system 10 stops generating power, if the residual pressure of hydrogen gas in the main tank 30 is above the operating limit pressure but below the starting limit pressure, the fuel cell system 10 cannot be started and power generation cannot be resumed, and the utilization efficiency of the hydrogen gas stored in the main tank 30 decreases.

[0044] As a countermeasure, the gas supply system 20 according to this embodiment is provided with an auxiliary tank 40. The auxiliary tank 40 is a starting fuel tank that stores hydrogen gas as a starting fuel for the fuel cell system 10. This auxiliary tank 40 is capable of storing gas at a level above the starting limit pressure of the fuel cell system 10. In addition, the auxiliary tank 40 is, as an example, a gas tank that stores compressed hydrogen gas.

[0045] (Branch piping) The auxiliary tank 40 is connected to the supply pipe 22 via a branch pipe 42. The branch pipe 42 is connected between the first shut-off valve 36 and the second shut-off valve 38 in the supply pipe 22. In other words, the branch pipe 42 branches off from between the first shut-off valve 36 and the second shut-off valve 38 in the supply pipe 22.

[0046] The branch pipe 42 is equipped with an auxiliary tank pressure gauge 44 and a third on-off valve 46. The auxiliary tank pressure gauge 44 is located between the auxiliary tank 40 and the third on-off valve 46 in the branch pipe 42. In other words, the auxiliary tank pressure gauge 44 is located upstream of the third on-off valve 46 in the branch pipe 42.

[0047] The auxiliary tank pressure gauge 44 detects the supply pressure of hydrogen gas supplied from the auxiliary tank 40 to the fuel cell system 10 via the pressure reducing valve 24. The auxiliary tank pressure gauge 44 is electrically connected to the control device 80, which will be described later.

[0048] The third on-off valve 46 is located downstream of the auxiliary tank pressure gauge 44 in the branch piping 42. This third on-off valve 46 opens and closes the branch piping 42. The control device 80, which will be described later, is electrically connected to the third on-off valve 46.

[0049] (Control device) The control device 80 controls the overall operation of the gas supply system 20 (see Figure 1). The control device 80 is implemented, for example, by the computer shown in Figure 2. This control device 80 includes a CPU (Central Processing Unit) 82, a memory 84 as a temporary storage area, a non-volatile storage unit 86, and an input / output device 88. These CPU 82, memory 84, storage unit 86, and input / output device 88 are connected to each other via a bus 89. The CPU 82 is an example of a control unit and processor.

[0050] The storage unit 86 is implemented by, for example, an HDD (Hard Disk Drive), an SSD (Solid State Drive), flash memory, etc. The storage unit 86, as a recording medium, has a control program pre-stored in it that controls the operation of the control device 80.

[0051] The CPU 82 reads the control program from the memory unit 86, loads it into the memory 84, and sequentially executes each step of the control program.

[0052] As shown in Figure 3, the control device 80 is electrically connected to the fuel cell system 10, the supply pressure gauge 34, the first shut-off valve 36, the second shut-off valve 38, the third shut-off valve 46, and the auxiliary tank pressure gauge 44 via wired or wireless connections.

[0053] (Fuel supply processing in the fuel supply system) Next, the fuel supply process of the gas supply system 20 will be described.

[0054] When the fuel cell system 10 is started up, the gas supply system 20 performs the gas supply process shown in Figures 4 and 7. Note that the gas supply process is just one example of a fuel supply method. Furthermore, in the following, each step of the gas supply process will be described with reference to Figures 4 and 7.

[0055] As shown in Figure 1, in the initial state of the gas supply system 20, the first shut-off valve 36, the second shut-off valve 38, and the third shut-off valve 46 are closed. In the following, the first shut-off valve 36, the second shut-off valve 38, and the third shut-off valve 46 in their closed state are colored black, while the first shut-off valve 36, the second shut-off valve 38, and the third shut-off valve 46 in their open state are shown as white.

[0056] From this state, as shown in Figure 5, first, in step S10, the CPU 82 opens the first shut-off valve 36 and the second shut-off valve 38 of the supply pipe 22. As a result, hydrogen gas is supplied from the main tank 30 to the fuel cell system 10 via the supply pipe 22. At this time, the pressure reducing valve 24 reduces the hydrogen gas supplied from the main tank 30 to the fuel cell system 10 to a predetermined value.

[0057] Next, in step S12, the CPU 82 obtains the supply pressure of the main tank 30 as detected by the supply pressure gauge 34.

[0058] Next, in step S14, the CPU 82 determines whether the supply pressure of the main tank 30 is equal to or greater than the starting limit pressure of the fuel cell system 10. If the CPU 82 determines that the supply pressure of the main tank 30 is equal to or greater than the starting limit pressure of the fuel cell system 10 (main tank supply pressure ≥ starting limit pressure), the process proceeds to step S16.

[0059] Next, in step S16, the CPU 82 obtains the supply pressure of the auxiliary tank 40 detected by the auxiliary tank pressure gauge 44.

[0060] Next, in step S18, the CPU 82 determines whether the supply pressure of the auxiliary tank 40 is equal to or greater than the starting limit pressure of the fuel cell system 10. If the CPU 82 determines that the supply pressure of the auxiliary tank 40 is equal to or greater than the starting limit pressure of the fuel cell system 10 (supply pressure of auxiliary tank ≥ starting limit pressure), it terminates the process with the first on-off valve 36 and the second on-off valve 38 open.

[0061] This supplies hydrogen gas at a pressure exceeding the starting limit from the main tank 30 to the fuel cell system 10. As a result, the fuel cell system 10 starts up and begins generating electricity.

[0062] (If the conditions in step S18 are not met) On the other hand, in step S18, if the CPU 82 determines that the supply pressure of the auxiliary tank 40 is less than the starting limit pressure of the fuel cell system 10 (supply pressure of auxiliary tank < starting limit pressure), the process proceeds to step S20 and the filling process of the auxiliary tank 40 is executed.

[0063] (Filling process for auxiliary tanks) Specifically, as shown in Figure 6, in step S20, the CPU 82 opens the third on-off valve 46. This allows hydrogen gas to be supplied from the main tank 30 to the auxiliary tank 40 via the branch pipe 42, and the auxiliary tank 40 is filled with hydrogen gas.

[0064] Next, in step S22, the CPU 82 obtains the supply pressure of the auxiliary tank 40 detected by the auxiliary tank pressure gauge 44.

[0065] Next, in step S24, the CPU 82 determines whether the supply pressure of the auxiliary tank 40 is equal to or greater than the starting limit pressure of the fuel cell system 10. If the CPU 82 determines that the supply pressure of the auxiliary tank 40 is equal to or greater than the starting limit pressure of the fuel cell system 10 (supply pressure of auxiliary tank ≥ starting limit pressure), the process proceeds to step S26.

[0066] Next, as shown in Figure 5, in step S26, the CPU 82 closes the third on-off valve 46. This stops the supply of hydrogen gas from the main tank 30 to the auxiliary tank 40 via the branch pipe 42. The auxiliary tank 40 is then filled (stored) with hydrogen gas at a level exceeding the starting limit pressure of the fuel cell system 10.

[0067] The CPU 82 then terminates processing with the first on-off valve 36 and the second on-off valve 38 open. As a result, hydrogen gas at a pressure above the starting limit pressure is supplied from the main tank 30 to the fuel cell system 10, as described above. Consequently, the fuel cell system 10 starts up and begins generating electricity.

[0068] (If the conditions in step S24 are not met) In step S24, if the CPU 82 determines that the supply pressure of the auxiliary tank 40 is less than the starting limit pressure of the fuel cell system 10 (supply pressure of auxiliary tank < starting limit pressure), it returns to step S22 after a predetermined time has elapsed.

[0069] (If the conditions in step S14 are not met) In step S14, if the CPU 82 determines that the supply pressure of the main tank 30 is less than the starting limit pressure of the fuel cell system 10, it proceeds to step S30 shown in Figure 7.

[0070] Next, in step S30, it is determined whether the supply pressure of the main tank 30 is equal to or greater than the operating limit pressure of the fuel cell system 10. If the CPU 82 determines that the supply pressure of the main tank 30 is equal to or greater than the operating limit pressure of the fuel cell system 10 (main tank supply pressure ≥ operating limit pressure), it proceeds to step S32.

[0071] Next, in step S32, the CPU 82 obtains the supply pressure of the auxiliary tank 40 detected by the auxiliary tank pressure gauge 44.

[0072] Next, in step S34, the CPU 82 determines whether the supply pressure of the auxiliary tank 40 is equal to or greater than the starting limit pressure of the fuel cell system 10. If the CPU 82 determines that the supply pressure of the auxiliary tank 40 is equal to or greater than the starting limit pressure of the fuel cell system 10 (supply pressure of auxiliary tank ≥ starting limit pressure), the process proceeds to step S36.

[0073] Next, as shown in Figure 8, in step S36, the CPU 82 closes the first on-off valve 36 and opens the third on-off valve 46. As a result, hydrogen gas at a starting limit pressure or higher is supplied from the auxiliary tank 40 to the fuel cell system 10 via the branch pipe 42 and the supply pipe 22. Consequently, the fuel cell system 10 starts up and begins generating electricity.

[0074] Next, in step S38, the CPU 82 determines whether the fuel cell system 10 has started up, for example, by checking whether or not the fuel cell system 10 is generating power. If the CPU 82 determines that the fuel cell system 10 has started up, it proceeds to step S40.

[0075] Next, as shown in Figure 5, in step S40, the CPU 82 opens the first on-off valve 36 and closes the third on-off valve 46, thereby ending the process.

[0076] As a result, hydrogen gas at or above the operating limit pressure is supplied to the fuel cell system 10 from the main tank 30 via the supply pipe 22, instead of the auxiliary tank 40. Consequently, power generation continues in the fuel cell system 10.

[0077] (If the conditions in step S38 are not met) In step S38, if the CPU 82 determines that the fuel cell system 10 has not started, it will execute step S38 again after a predetermined time has elapsed.

[0078] (If the conditions in step S30 are not met) In step S30, if the CPU 82 determines that the supply pressure of the main tank 30 is less than the operating limit pressure of the fuel cell system 10 (main tank supply pressure < operating limit pressure), the CPU proceeds to step S42.

[0079] As shown in Figure 1, in step S42, the CPU 82 closes the first on-off valve 36 and the second on-off valve 38.

[0080] Next, in step S44, the CPU 82 terminates the process by displaying a message (startup error) to the input / output device 88, for example, indicating that the fuel cell system 10 cannot be started.

[0081] (If the conditions in step S34 are not met) In step S34, if the CPU 82 determines that the supply pressure of the auxiliary tank 40 is less than the starting limit pressure of the fuel cell system 10 (supply pressure of auxiliary tank < starting limit pressure), it proceeds to step S42 as described above.

[0082] Furthermore, if the CPU 82 detects that the fuel cell system 10 has stopped generating power after or during the execution of the above gas supply process, it closes the first shut-off valve 36 and the second shut-off valve 38.

[0083] (effect) Next, the effects of this embodiment will be described.

[0084] As described above, the CPU 82, acting as the control unit, switches between the main tank 30 and the auxiliary tank 40 to supply hydrogen gas to the fuel cell system 10, based on the supply pressure of hydrogen gas supplied from the main tank 30 to the fuel cell system 10, the starting limit pressure of the fuel cell system 10, and the operating limit pressure.

[0085] Specifically, when starting the fuel cell system 10, the CPU 82 supplies hydrogen gas from the main tank 30 to the fuel cell system 10 if the supply pressure of hydrogen gas supplied from the main tank 30 to the fuel cell system 10, i.e., the supply pressure of hydrogen gas detected by the supply pressure gauge 34, is equal to or greater than the starting limit pressure. This allows the fuel cell system 10 to start up.

[0086] Furthermore, the CPU 82 opens the third shut-off valve 46 when the supply pressure of hydrogen gas supplied from the auxiliary tank 40 to the fuel cell system 10, i.e., the supply pressure detected by the auxiliary tank pressure gauge 44, is below the starting limit pressure. This allows hydrogen gas to be supplied from the main tank 30 to the auxiliary tank 40. Therefore, the auxiliary tank 40 can store hydrogen gas at or above the starting limit pressure of the fuel cell system 10.

[0087] On the other hand, when the hydrogen gas supply pressure detected by the supply pressure gauge 34 is below the starting limit pressure and above the operating limit pressure, the CPU 82 closes the first on-off valve 36 and opens the third on-off valve 46. This allows hydrogen gas at or above the starting limit pressure to be supplied from the auxiliary tank 40 to the fuel cell system 10.

[0088] Therefore, even if the supply pressure of hydrogen gas supplied from the main tank 30 to the fuel cell system 10 is below the starting limit pressure, the fuel cell system 10 can be started.

[0089] Furthermore, after the fuel cell system 10 is started, the CPU 82 opens the first on-off valve 36 and closes the third on-off valve 46. This supplies hydrogen gas at or above the operating limit pressure from the main tank 30 to the fuel cell system 10. In other words, the hydrogen gas remaining in the main tank 30 can be utilized.

[0090] Thus, in this embodiment, the utilization efficiency of the hydrogen gas stored in the main tank 30 can be increased with a simple configuration of supplying hydrogen gas from the auxiliary tank 40 to the fuel cell system 10.

[0091] Furthermore, in this embodiment, the main tank 30 is a hydrogen storage alloy tank. This makes it possible to miniaturize the main tank 30 while increasing the utilization efficiency of the hydrogen gas absorbed by the hydrogen storage alloy within the main tank 30.

[0092] (modified version) Next, a modified example of the above embodiment will be described.

[0093] In the above embodiment, the supply pressure of the gas supplied from the main tank 30 or auxiliary tank 40 to the fuel cell system 10, as well as the starting limit pressure and operating limit pressure of the fuel cell system 10, may be values ​​obtained by multiplying them by, for example, a safety factor. In other words, the CPU 82, acting as the control unit, can control the operation of the gas supply system 20, including the first on-off valve 36, the second on-off valve 38, and the third on-off valve 46, based on the supply pressure of the gas supplied from the main tank 30 or auxiliary tank 40 to the fuel cell system 10, and the starting limit pressure and operating limit pressure of the fuel cell system 10.

[0094] Furthermore, in the above embodiment, the gas supply process includes the filling process of the auxiliary tank. However, if the auxiliary tank 40 is pre-filled with hydrogen gas at or above the starting limit pressure, the filling process of the auxiliary tank can be omitted.

[0095] Furthermore, in the above embodiment, the tank supplying hydrogen gas to the fuel cell system 10 is switched between the main tank 30 and the auxiliary tank 40 by the first on-off valve 36, the second on-off valve 38, and the third on-off valve 46. However, the main tank 30 and the auxiliary tank 40 are not limited to the first on-off valve 36, the second on-off valve 38, and the third on-off valve 46; they may also be switched by, for example, a three-way valve.

[0096] Furthermore, in the above embodiment, the main tank 30 is a hydrogen storage alloy tank. However, the main tank 30 is not limited to a hydrogen storage alloy tank; for example, it may be a gas tank for storing compressed hydrogen gas, or a liquid hydrogen storage tank for storing liquid hydrogen.

[0097] Furthermore, in the above embodiment, the auxiliary tank 40 is a gas tank. However, the auxiliary tank 40 is not limited to a gas tank; for example, it may be a hydrogen storage alloy tank or a liquid hydrogen storage tank.

[0098] Furthermore, in the above embodiment, the utilization device is a fuel cell system 10 that uses hydrogen gas as fuel. However, the utilization device is not limited to a fuel cell system 10, but may also be, for example, a gas combustion engine, a gas turbine, a gas station, etc. In this case, the main tank 30 and the auxiliary tank 40 store gas according to the fuel of the utilization device.

[0099] Furthermore, in the above embodiments, the term "processor" refers to a broad type of processor, including general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0100] Furthermore, the processor operation in the above embodiment may not be performed by a single processor, but may be performed by multiple processors located in physically separate locations working together. Also, the order of each processor operation is not limited to the order described in the above embodiment, but may be changed as appropriate. In addition, some or all of the processors may be configured on the cloud. At least each of the processes described in the above embodiment may be executed by a processor on the cloud.

[0101] Furthermore, although the above embodiments describe a configuration in which each program is installed in ROM or storage, the invention is not limited to this. Each program according to the above embodiment may be provided in a form recorded on a computer-readable storage medium. For example, each program according to the above embodiment may be provided in a form recorded on an optical disc such as a CD (Compact Disc)-ROM or DVD (Digital Versatile Disc)-ROM, or in a form recorded on a semiconductor memory such as a USB (Universal Serial Bus) memory or memory card. In addition, each program according to the above embodiment may be acquired from an external device via a communication interface.

[0102] Furthermore, while the above embodiment describes a case in which the processing in the gas supply system 20 is realized by a software configuration using a computer by executing a program, this disclosure is not limited thereto. For example, the processing in the gas supply system 20 may also be realized by a hardware configuration or a combination of a hardware configuration and a software configuration.

[0103] Furthermore, the configuration of the gas supply system 20 described in the above embodiment is merely an example, and it goes without saying that unnecessary parts may be deleted or new parts added without departing from the spirit of this disclosure.

[0104] Furthermore, the processing flow in the gas supply system 20 described in the above embodiment is just one example, and it goes without saying that unnecessary steps may be deleted, new steps added, or the processing order rearranged without departing from the spirit of this disclosure. Moreover, the program in the above embodiment may be provided as a program product.

[0105] Although one embodiment of the present invention has been described above, the present invention is not limited to these embodiments, and various modifications may be used in appropriate combinations with one embodiment, and of course, the invention can be implemented in various forms without departing from the spirit of the present invention. [Explanation of Symbols]

[0106] 10. Fuel cell systems (devices used) 20 Gas supply systems 30 Main tank 40 Auxiliary tanks 82 CPU (Control Unit)

Claims

1. A main tank for storing the gas supplied to the equipment, An auxiliary tank for storing gas at or above the starting limit pressure of the aforementioned device, A control unit that switches between the main tank and the auxiliary tank which tank supplies gas to the utilization device based on the supply pressure of the gas supplied from the main tank to the utilization device, the starting limit pressure of the utilization device, and the operating limit pressure of the utilization device which is lower than the starting limit pressure, A gas supply system equipped with the following features.

2. The control unit, When the utilization device is started, if the supply pressure of the gas supplied from the main tank to the utilization device is less than the starting limit pressure and greater than or equal to the operating limit pressure, gas will be supplied from the auxiliary tank to the utilization device. After the utilization device is started, gas is supplied from the main tank to the utilization device. The gas supply system according to claim 1.

3. The control unit, When the utilization device is started, if the supply pressure of the gas supplied from the main tank to the utilization device is equal to or greater than the starting limit pressure, the gas is supplied from the main tank to the utilization device. If the supply pressure of the gas supplied from the auxiliary tank to the utilization device is less than the starting limit pressure, the gas is supplied from the main tank to the auxiliary tank. A gas supply system according to claim 1 or claim 2.

4. The main tank is a hydrogen storage alloy tank. The aforementioned auxiliary tank is a hydrogen gas tank. The gas supply system according to claim 1.

Images